Headrest for a bathtub



FIG. 1 is a top perspective view of a headrest for a bathtub, showing my new design;

FIG. 2 is a reduced top perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a left side elevational view thereof, the right side being a mirror image of the left side;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a rear elevational view thereof.

The fragmentary broken line representation of a bathtub in FIG. 2 and the broken line representation of suction cups in FIGS. 4, 5 and 6 are for purposes of illustration only and form no part of the claimed design. 

The ornamental design for a headrest for a bathtub, as shown and described. 